I happen to fit the profile of someone to watch out for in the airports. I must, because I get searched thoroughly every time I fly. A couple of times twice...once at the first terminal where I am (like always) pulled aside and have my carry-on looked through...and a few times twice where I was pulled out of line while starting to board the aircraft and searched again. I even asked one time what profile I fit, but was told it was random...I doubt it.
In my opinion, I am the last person that would fit any negative profile. I just dont stand out. Short hair, no tattoos, about 1/4 German then a mix of about every Euro-Trash lineage there is...plus a little Fox Indian to boot. I tend to dress like a typical bedwetting yuppie.
Anyways, to get to the point, one time when my baggage was getting checked for explosive residue I told the person that I was a firearms collector and wondered if blackpowder or smokeless powder would trip the sensors...I was told it would not...it looked for other substances.
Just my experience, FWIW. The person I talked to could have been a moron, or lying. Or both. :-)